424 



THE WONDERS OF GEOLOGY. 



Lect. IV. 



derms.* The enamel was thick in front and thin behind, 

 by which arrangement a sharp cutting edge must have been 

 maintained in every stage of use. There was no fang, but 



Lign. 102. — Teeth of the Iguanodon : from Tilgate Forest. 



Filt. 1. The inner, and 3, the outer, aspect of a tooth worn flat, and the fang 

 absorbed. 

 2. Tooth of a young animal. 



4. Outer, and 5, inner, surface of a tooth of an adult. 

 6. Lateral view of the serrated edge of fig. 5, magnified. 

 <7, The surface worn by mastication. 

 <*, The indentation produced by the pressure of the new tooth. 



* This specimen was submitted to the examination of Baron Cuvier 

 by my friend Mr. Lyell, at that time in Paris ; and M. Cuvier pro- 

 nounced it to be an upper incisor of a rhinoceros ; and it was not till 

 I had collected an entire series of teeth in various states of detrition, 

 that the correctness of my opinion was admitted, either as to the 

 nature of the fossil, or the geological position of the stratum in which 

 it was found. See Ossemens Fossiles, torn. v. p. 351. 



